Nicola Spampinato

Aortic Valve Replacement: A Prospective Randomized Evaluation of Mechanical Versus Biological Valves in Patients Ages 55 to 70 Years

OBJECTIVES The aim of this study was to determine long-term results between bioprosthetic (BP) and mechanical (MP) aortic valves in middle-aged patients. BACKGROUND It has not been established which is the best aortic valve substitute in patients ages 55 to 70 years. We conducted a randomized study to compare long-term outcomes between BP and MP aortic valves. METHODS Between January 1995 and June 2003, 310 patients were randomized to receive a BP or an MP aortic valve. Primary end points of the study were survival, valve failure, and reoperation. RESULTS One hundred fifty-five patients received a BP valve, and 155 patients received an MP valve. Four patients died, perioperatively, in the MP group (2.6%), and 6 patients died in the BP group (3.9%, p = 0.4). At late follow-up (mean 106 +/- 28 months) 41 patients died in the MP group and 45 patients died in the BP group (p = 0.6). There was no difference in the survival rate at 13 years between the MP and BP groups. Valve failures and reoperations were more frequent in the BP group compared with the MP group (p = 0.0001 and p = 0.0003, respectively). There were no differences in the linearized rate of thromboembolism, bleeding, endocarditis, and major adverse prosthesis-related events (MAPE) between the MP and BP valve groups. CONCLUSIONS At 13 years, patients undergoing aortic valve replacement either with MP or BP valves had a similar survival rate as well the same rate of occurrence of thromboembolism, bleeding, endocarditis, and MAPE, but patients who had undergone aortic valve replacement with BP valves faced a significantly higher risk of valve failure and reoperation.

Thoracic aortic emergencies: impact of endovascular surgery.

BACKGROUND Conventional surgery for thoracic aortic emergencies, such as contained or free rupture of thoracic aortic aneurysms, acute type B dissections, and traumatic rupture of the thoracic aorta, is frequently associated with a high rate of mortality and morbidity. To obviate this risk, endovascular surgery is considered to be a valid alternative procedure. METHODS From March 2001 to July 2002, 15 of 22 patients with acute thoracic aortic syndromes were submitted to endovascular surgery: 3 patients (20%) for traumatic rupture, 4 patients (26.7%) for contained or free rupture of thoracic aortic aneurysm, and 8 patients (53.3%) for acute type B dissection evolving to rupture. Computed tomographic scan was diagnostic in all patients. The stent grafts were introduced through the femoral artery. RESULTS In the endovascular group there were no perioperative deaths or open conversions. The intraoperative angiography and computed tomographic scan performed on discharge showed no significant endoleaks and successful sealing of the aortic dissection. Average intensive care unit and hospital stay was 1.7 +/- 0.8 and 5.9 +/- 3.0 days. Follow-up ranged between 4 and 23 months and included clinical examinations and serial computed tomographic scan at 3, 6, and 12 months, and every 6 months thereafter. One 84-year-old patient with thoracic aortic aneurysm died of pneumonia 78 days after endovascular surgery. Only one type 1 endoleak was noted in the first patient with traumatic rupture, 3 months after the procedure. CONCLUSIONS Endovascular surgery is a safe technique, showing encouraging early and midterm results and allowing for prompt treatment of associated lesions in complex multitrauma patients.

Role of catheter-induced mechanical trauma in localization of target sites of radiofrequency ablation in automatic atrial tachycardia

OBJECTIVES We compared the efficacy of two different mapping techniques in identifying the ablation site for atrial tachycardia. Moreover, we evaluated the additive positive predictive value of mechanical interruption of atrial tachycardia to reduce the number of ineffective radiofrequency applications. BACKGROUND Radiofrequency catheter ablation has been suggested as a highly effective technique to treat drug-resistant atrial tachycardia. However, irrespective of the mapping technique utilized, success was most often achieved with a large number of radiofrequency applications. METHODS Forty-five patients with atrial tachycardia underwent radiofrequency catheter ablation. Mapping techniques included identification of earliest atrial activation and pace-mapping concordant sequence. RESULTS Atrial tachycardia was successfully treated in 42 (93.3%) of 45 patients with a mean of 3.9 radiofrequency pulses/patient. An interval between the onset of the intracavitary atrial deflection and the onset of the P wave during atrial tachycardia (AP interval) > or = 30 ms (p < 0.001) and pace-mapping concordant sequence (p = 0.01) were all significant predictors of outcome. An AP interval > or = 30 ms and a pace-mapping concordant sequence were highly sensitive (92.8%, 95% confidence interval [CI] 80.5% to 98.5%; 85.7%, 95% CI 71.5% to 94.6%, respectively) but less specific (47.8%, 95% CI 37.9% to 58.2%, 36.8%, 95% CI 27.6% to 47.2%, respectively) in identifying the site of ablation. By using atrial tachycardia mechanical interruption combined with the AP interval >30 ms or the pace-mapping concordant sequence, we obtained a specifically of 76.5% (95% CI 66.4% to 84.0%) and 73.5% (95% CI 63.2% to 81.4%), respectively, and a positive predictive value of 49.2% and 44.6%, respectively. CONCLUSIONS An AP interval > or = 30 ms and a pace-mapping concordant sequence were reliable mapping features for predicting the outcome of the ablation procedure. Mechanical interruption of atrial tachycardia improved the specificity and positive predictive value of these two mapping techniques.

Protection by coenzyme Q10 from myocardial reperfusion injury during coronary artery bypass grafting

To evaluate the effect of coenzyme Q10 in reducing postoperative cardiac complications after ischemia and reperfusion, we randomly divided 40 patients undergoing elective coronary artery bypass into two groups: patients in group 1 received coenzyme Q10 (150 mg/day) for 7 days before operation, and those in group 2 were the control group. Concentrations of thiobarbituric acid-reactive substances (malondialdehyde), conjugated dienes, and cardiac isoenzymes of creatine kinase were measured in samples from both arterial and coronary sinus sites. Serial sampling was performed 5 minutes after heparin administration, at 10 and 30 minutes during cardiopulmonary bypass, 15 and 30 minutes after aortic cross-clamp removal, and 5 minutes after protamine administration. The concentrations of malondialdehyde, conjugated dienes, and creatine kinase in group 1 were significantly lower than those in group 2. The decrease in plasma malondialdehyde concentrations correlated positively with the decrease in creatine kinase levels in the coronary sinus. The treatment group showed a significantly lower incidence of ventricular arrhythmias during the recovery period than did the control group (p < 0.05). Although the percentage of patients requiring inotropic agents was not significantly different between the two groups, the mean dosage of dopamine required to maintain stable hemodynamics was significantly lower in patients of group 1 than in those of group 2 (p < 0.01). Our findings suggest that pretreatment with coenzyme Q10 may play a protective role during routine bypass grafting by attenuating the degree of peroxidative damage.

One-stage coronary and abdominal aortic operation with or without cardiopulmonary bypass: early and midterm follow-up

BACKGROUND The aim of this study was to compare hospital, early, and late clinical outcomes for patients undergoing one-stage, coronary and abdominal aortic surgical intervention with and without cardiopulmonary bypass. METHODS From March 1990 to September 1999, 42 consecutive patients underwent combined operations at a single institution. Cardiopulmonary bypass and cardioplegic arrest were used during coronary revascularization in the first 20 patients (on-pump group), and the next 22 patients received the one-stage operations on the beating heart (off-pump group). RESULTS Baseline characteristics were similar between groups. Three cardiac-related hospital deaths occurred in the on-pump group and one such death in the off-pump group (p = 0.25). Cardiac-related events, pulmonary complications, inotropic support, blood loss and transfusion requirements, intensive care unit stay, and hospital stay were significantly reduced in the off-pump group (all, p < 0.05). The actuarial survival rates in the on-pump and off-pump groups were 80% and 95%, respectively, at 1 year (p = 0.13) and 75% and 89%, respectively, at 3 years (p = 0.22). Freedom from cardiac-related events at 1-year follow-up was 91% in the off-pump group and 65% in the on-pump group (p < 0.05). No difference in cardiac-related events between groups was observed at 3 years. CONCLUSIONS Off-pump coronary surgical procedures decrease postoperative complications in high-risk patients undergoing simultaneous coronary and abdominal aortic operations compared with the conventional one-stage procedure. The early benefits achieved with off-pump surgical intervention are not at the expense of the long-term clinical outcome.

Heterogeneity of left ventricular filling dynamics in hypertrophic cardiomyopathy

Abstract In conclusion, the data confirm that the pattern of filling velocities is nonuniform within the left ventricle in HC and depends on the degree of septal thickness; this nonuniformity is probably the outcome of nonuniform relaxation8 and stiffness.9 Moreover, filling dynamics in the left ventricle can be relevant because some patients with normal patterns of filling at the mitral level had an abnormal pattern of filling velocities near the septum.

Intermittent Warm Blood Cardioplegia Preserves Myocardial β-Adrenergic Receptor Function

BACKGROUND Left ventricular dysfunction is frequently observed in patients after hypothermic cardioplegic arrest, and often inotropic intervention is necessary for patients to be successfully weaned from cardiopulmonary bypass (CPB). A myocardial beta-adrenergic receptor (beta AR) desensitization has been noted to occur after hypothermic CPB in patients undergoing coronary artery bypass grafting. This randomized study was undertaken to determine the effect of cardioplegic solution temperature on cardiac beta ARs. METHODS Two groups of patients (20 patients in each) scheduled for elective coronary artery bypass grafting underwent CPB with either intermittent warm or cold blood cardioplegia. The density of the beta ARs, the proportion of beta 1- to beta 2-adrenergic receptors, and the beta AR coupling capacity to adenylate cyclase were determined in specimens of the right atrial tissue at baseline, during CPB, and after discontinuation of CPB. Plasma concentrations of catecholamines were also measured in both arterial and coronary sinus samples. RESULTS In both cardioplegia groups, no significant modification in either the beta AR density or the proportion of beta 1- to beta 2-adrenergic receptors was detected. However, a significant decrease in adenylate cyclase activity after stimulation with isoproterenol was observed in the cold blood cardioplegia group during CPB (p < 0.01) and 30 minutes after its discontinuation (p < 0.05). Moreover, a significant decrease in adenylate cyclase activity during CPB was detected in this group after stimulation with sodium fluoride (p < 0.05), but this pattern was found to be completely reversed by 30 minutes after discontinuation of CPB. No modification in the basal or stimulated adenylate cyclase activity was observed in the warm blood cardioplegia group during or after CPB. CONCLUSIONS Our results confirm the finding from previous studies of a cardiac beta AR desensitization after hypothermic cardioplegic arrest, and provide evidence of the advantages of intermittent warm blood cardioplegia in preserving the autonomic sympathetic function of the heart.

Low dose aprotinin as blood saver in open heart surgery

Bleeding after open heart surgery is still a great concern for the surgeon, especially when the surgical field has been revised accurately and hemostatic stitches and electrical cauterization have been used extensively. Among non-surgical adjuncts, aprotinin has been reported as very effective in reducing complications. At the time we started using this drug, we intended to test two different dosages lower than those reported in the literature. We evaluated three groups of 18 patients: the first (A) received about 350 mg of aprotinin from the start of anesthesia up to the end of operation (140 mg in the priming of cardio-pulmonary bypass and 70 mg/h i.v. during the procedure; the second (A/2) received half that dose (i.e. 70 mg and 35 mg, respectively), and the third (C) did not receive aprotinin. We compared in these groups: postoperative bleeding, blood transfusions, red blood cells, hemoglobin, hematocrit, platelets. The results were good only in the A group: bleeding was reduced and few transfusions were required. The patients in the A/2 and C groups did not show significant differences. From our observations we conclude that aprotinin is a useful adjunct, but has to be given in the proper dose.

Determinants of aortic artifacts during transesophageal echocardiography of the ascending aorta

BACKGROUND The origin of artifacts of the ascending aorta during transesophageal echocardiography has not been widely studied. This study was undertaken to investigate in vivo whether anatomic features could determine the appearance of artifacts. METHODS AND RESULTS Transesophageal echocardiograms of 46 patients studied for suspected dissection with proven diagnosis (30 patients with and 16 without ascending aortic dissection) were reviewed. The incidence of artifacts was 46%, and it was similar in patients with and those without dissection (chi-square 0.516; P = not significant). Artifacts were located in the aortic lumen twice as far from the transducer as the atrial-aortic interface. The aortic diameter was larger in patients with than in those without artifacts (6.4 +/- 1.1 vs 4.2 +/- 0.9 cm, P <.001). An aortic diameter >5 cm and an atrial-aortic ratio </=0.6 predicted the artifact appearance with good sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy; these parameters reached a value of 100% by analysis only of patients without dissection. CONCLUSIONS An ascending aortic diameter >5.0 cm that exceeds the left atrial diameter with an atrial-aortic ratio </=0.6 creates in vivo the conditions for the reverberation of the atrial-aortic interface within the aorta. Therefore, in patients with such anatomic features, artifacts must be suspected in the presence of linear structures within the aorta.

Massive air embolism during cardiopulmonary bypass: successful treatment with immediate hypothermia and circulatory support.

Two patients experienced an episode of massive air embolism during extracorporeal circulation. Several emergency measures were taken. (1) The roller pump was reversed to take out air from the aorta. (2) The circuit was disconnected and recirculated to eliminate air bubbles. (3) Perfusion was restarted and the patient cooled to 24 degrees C for 40 minutes. (4) Pentothal (thiopental), steroids, and assisted ventilation were administered. The outcome was favorable in both patients, and there were no neurological sequelae. Immediate cooling and prolonged circulation seem to be a satisfactory approach to this problem.